The present invention relates to a method of measuring radioactivity and, more particularly, to a method of measuring radioactivity which is suitable for discriminating between surface and internal contaminations of a body.
In the prior art, the quantity of radioactive substances taken into a human body is measured by bioassay or by a human counter. The former is a method by which the total quantity of radioactive substances in the body is deduced from the quantity of radioactive substances contained in the breath or urine, and the latter is a method by which the total quantity of radioactive substances in the body is measured by a plurality of radiation detectors positioned outside the body. In either method, the total quantity of radioactive substances within the body at the time of measurement is measured. However, neither method can discriminate which region has been contaminated by the radioactivity.